But then why wasn't the spike on Monday?
Bank holiday in the U.S.?
Two to three business days for funds to clear transfer in other parts of the world?
+1 to the bank holiday. I think demand lags news in some ways as well since many of the means for newcomers to buy bitcoins requires a week or more of verifications and transfers. Coinbase has limits. Mtgox has a verification period and if you're buying via Dwolla you need to get set up there. etc.